128 PROCEEDINGS OF THE PALEONTOLOGICAL SOCIETY 



SO that three faunas existed simultaneously in New York — the Naples in the 

 west, the Lower Portage, or pure Ithaca, in the center, and the Hamilton in 

 the east. Submergence of the bar permitted an intermingling of the Hamil- 

 ton and pure Ithaca faunas, and so produced the mixed fauna commonly taken 

 as typical (but not the pure) Ithaca fauna. These facts are demonstrated by 

 showing the percentages of each of the faunal units found in the successive 

 sections from west to east. 



Professor Moore, a visiting Fellow of the Geological Society of Amer- 

 ica, then gave an interesting account of algal limestones of the Far North. 

 His paper was illustrated by lantern slides and was discussed by Messrs. 

 White, Merriam, Grabau, and Bassler. 



ALGAL LIMESTOXE OX THE BELCHER ISLANDS, HUDSON BAY 

 BY E. S. MOORE* 



(Ahstraet) 



The Belcher Islands are situated off the east coast of Hudson Bay and con- 

 sist of rocks similar in many respects to those formed on the coast and which 

 have been described by Leith and Low, The islands were little known until 

 recently, when considerable areas of jasper were discovered on them. Asso- 

 ciated with this iron formation there is a remarkable band of concretionary 

 limestone over 400 feet thick and consisting of spherical to subspherical balls 

 varying from about an inch to 15 inches in diameter. These were at first re- 

 garded as cryptozoons. but their spherical form and the almost total absence of 

 the crenulated character of the cryptozoons seem to separate them, at least 

 from Cryptozoon proUferum. They resemble more strongly some of the recent 

 algal concretions found in lakes and streams and described by Clarke, Roddy, 

 and others. A smaller type is similar in some respects to Walcott's Colleniaf 

 frequens. 



In the associated iron formation there are numerous granules of calcite, 

 silica, and iron silicate. The two former bear a close resemblance to certain 

 granules which occur in the Lower Paleozoic limestones of central Pennsyl- 

 vania and which grade without break into distinct oolites. The occurrence of 

 these concretions, both large and small, and their associations point strongly 

 to organic origin of the limestone and iron deposits, and it indicates further 

 that these rocks are either not Precambrian, as they have been supposed to 

 be, or that an abundance of low tj'pes of life existed in the Hudson Bay basin 

 in Precambrian time. 



At 12.30 p. m. the Society adjourned for luncheon, convening again 

 at 2 p. m. for the reading of the paleobotanic papers of the symposium. 

 Although the absence of several of the authors prevented a full discus- 

 sion of their papers, wliich were read by other members of the Society, a 

 number of interesting and instructive points were brought out in the 

 remarks by Messrs. Matthew, Vaughan, White, Merriam, Ami, Osborn, 

 and others. 



[ntroduced by H. S. Bassler. 



